proteins

Zona pellucida

..., is responsible for sperm binding, adhering to proteins on the sperm plasma membrane. There is evidence that ZP3 is then involved in the induction of the acrosome reaction, whereby a spermatozoon releases the contents of the acrosomal vesicle . Reference Oehninger S. 2003. Biochemical and function...

X-ray crystallography

...lecules, including inorganic compounds, DNA and proteins . Contents showTocToggle("show","hide") 1 Inorganic Structures 2 Organic Structures 3 See also 4 Paper Resources/Books Inorganic Structures X-ray diffraction finds frequent use in materials science because sample p...

Vitamin

...ontained "accessory factors"—in addition to proteins , carbohydrates , fats , etc.—that were necessary to the human body. When Kazimierz Funk isolated the chemical that Fletcher had identified, he proposed that it be named "Vitamine". The name soon became synonymous with Hopkins' "accessory...

Virus

...ded by some form of protective coat consisting of proteins , lipids , and glycoproteins . Importantly viral genomes code not only for the proteins needed to package its genetic material , but for proteins needed by the virus during lysogenic a...

Virus classification

... an intermediate when genes are translated into proteins . RNA genomes of viruses can be encoded in two different directions: Either the genes are stored in the 5'->3' direction (positive or + polarity), analogous to the direction in which genes are represented in mRNA in cells, or the genes are stor...

Vesicle

...molecules between locations inside the cell, e.g., proteins from the endoplasmic reticulum to the Golgi appa...vature of a donor membrane, and to select specific proteins as cargo. It selects cargo proteins by binding to sorting signals . In this way the vesicle coat clu...

Vacuole

...rostatic pressure. Storage of organic compounds, proteins (in seeds), and inorganic ions (e.g., K + and C...es was discovered. Under conditions of starvation, proteins are degraded in vacuoles; this is called autophagy. First, cytoplasms , mitochondria , and small ...

Unsolved problems in biology

...complete structure and function of the proteome proteins expressed by a cell or organ at a particular time and under specific conditions? What is the complete function of the regulator genes ? The building block of life may be a precursor to a generation of electronic devices and computers , but wh...

Vaccine

...ecognize. By linking these unknown outer coats to proteins and toxins that reliably provoke an immune response Subunit - rather than introducing a whole inactivated or attenuated micro-organism to an immune system, a fragment of it can create an immune response Recombinant Vector - by combining the physi...

Transmembrane receptor

Transmembrane receptors are integral membrane proteins , which reside and operate typically within a cell...ecific protein-protein-interactions with effector proteins , which in turn send the signal along a signal chain to its destination. The intracellular domain...

Transmembrane protein

...and outside the cell or compartment. Transmembrane proteins often have their N-terminal on the exoplasmic face...rminal on the cytoplasmic face. Many transmembrane proteins have multiple membrane spanning alpha helix segments which anchors them to the membrane. Most tran...

Tobacco mosaic virus

... around the viral RNA in a helical structure (16.3 proteins per helix turn). The virions have a diameter ~18nm and an inner hole ~2nm. The protein coat consists of 158 aminoacids which are assembled into four main alpha-helices, which are joined by a prominent loop proximal to the axis of the virion. The RNA ...

Trait

...of traits The biochemistry of the intermediate proteins determines how they interact in the cell. Therefore, biochemistry predicts how combinations of different alleles will produce varying traits. Extended expression patterns seen in diploid organisms include facets of incomplete dominance , codo...

Tobacco mosaic virus

... around the viral RNA in a helical structure (16.3 proteins per helix turn). The virions have a diameter ~18nm and an inner hole ~2nm. The protein coat consists of 158 aminoacids which are assembled into four main alpha-helices, which are joined by a prominent loop proximal to the axis of the virion. The RNA ...

Mitosis

...phase. This is divided into two phases. First, the proteins that bind the sister chromatids together are cloven, allowing them to separate. They are pulled apart by the microtubules, towards the respective centrioles to which they are attached. Next, the spindle axis elongates, driving the centrioles (and the...

Tertiary structure

...lved in stabilizing the tertiary structure of many proteins is the disulfide bond . One goal of bioinformatics is to predict the native conformation of a protein from its primary sequence . Conventionally, tertiary structures are deduced through crystallography or multidimensional NMR . The study of...

Systems biology

... Genes , in the main, encode the proteins made within a cell . Theproperties of these cells can determine the diseases to which a person issusceptible. Therefore, a given disease exhibited by a patient might beexplained through reference to a gene that they might possess. In systemsbiol...

Synapse

...om the space for recycling by specialized membrane proteins in the pre-synaptic or post-synaptic membrane. Th...ses through such means as phosphorylation of the proteins involved. The size, number and replenishment rate of vesicles also are subject to regulation, as are...

Structural biology

...tecture and shape of biological macromolecules -- proteins and nucleic acids in particular--and what cause...uce aspects of the structure of integral membrane proteins based on the membrane topology predicted by hydrophobicity analysis . See: protein structure pre...

Splicing (genetics)

...r structures composed of small nuclear ribonuclear proteins (snRNPs (pronounced "snurps")), splice the 3' end ...cases, the splicing process can create many unique proteins from a large collection of exons. This phenomenon is called alternative splicing . XXXX EEEE II...

Endoplasmic reticulum

... found in all eukaryotic cells . The ER modifies proteins , makes macromolecules , and transfers substances...the translation and folding of and transport of proteins that are to become part of the cell membrane (e.g., transmembrane receptors and other integral...

Signal transduction

...o communicate across synapses , bind to receptor proteins in the membrane and open their ion channels . ... to further effects, since genes are expressed as proteins , many of which are enzymes, transcription factors or other regulators of metabolic activity. Beca...

Blood plasma

...ood cells are suspended. Blood plasma contains proteins , nutrients , metabolic end products , hormones...nt straw colour). It is mainly composed of water, proteins , and mineral salts. It serves as transport medium for glucose , lipids , hormones , products of ...

Second messenger

...r and pre-processed by other membrane-associated proteins . There are three basic types of second messenger ...n reach and regulate membrane-associated effector proteins . Hydrophilic molecules are water-soluble molecules, like cAMP , cGMP , and Ca 2+ , that ...

Secondary structure

...le actually listing the secondary structure of the proteins with known 3D structure (Kabsch and Sander 1983). ...ual use of sequence. Distant relationships amound proteins whose primary structures are unalignable can sometimes be found by secondary structure. Predicti...

Endoplasmic reticulum

... found in all eukaryotic cells . The ER modifies proteins , makes macromolecules , and transfers substances...the translation and folding of and transport of proteins that are to become part of the cell membrane (e.g., transmembrane receptors and other integral...

Endoplasmic reticulum

... found in all eukaryotic cells . The ER modifies proteins , makes macromolecules , and transfers substances...the translation and folding of and transport of proteins that are to become part of the cell membrane (e.g., transmembrane receptors and other integral...

Ribosome

...e or polysome . Free ribosomes usually produce proteins that are used in the cytosol or in the organelle ...cur in. Membrane bound ribosomes When certain proteins are synthesized by a ribosome, it can become "membrane-bound", associated with the membrane of the ...

RNA

... (via transcription ) and then translate it into proteins (by translation ). Contents showTocToggle...tter suited for storage of genetic information and proteins are better suited for the catalytic needs of cells, one would expect reduced use of RNA in cells, an...

Blood type

...ood cells due to substances ( carbohydrates and proteins ) on the cell membrane. The two most important classifications to describe blood types in humans are ABO and Rh factor . There are 46 other known antigens , most of which are much rarer than ABO and Rh. Blood transfusions from incompatible groups...

Retrovirus

...enomes commonly contain three genes , that encode proteins that can be found back in the mature virus: ga...ecific a nti g en) codes for core and structural proteins of the virus; pol ( pol ymerase) codes for reverse transcriptase , protease and integrase ;...

Reverse genetics

...et mRNA without requiring the activity of cellular proteins and without necessarily accelerating mRNA degradation. Morpholinos are effective is systems ranging in complexity from cell-free translation in a test tube to humans. Finally, a more difficult genetics technique is the creation of transgenic orga...

Quaternary structure

In biochemistry , many proteins are actually assemblies of more than one protein ...tiary structure of the subunits, multiple-subunit proteins possess a quaternary structure , which is the arrangement into which the subunits assemble. Enzyme...

Proteomics

Proteomics is the large-scale study of proteins , particularly their structures and functions. Th...fferent environmental conditions. The entirety of proteins in existence in an organism throughout its life cycle, or on a smaller scale the entirety of protein...

Proteolysis

...sis is the directed degradation ( digestion ) of proteins by cellular enzymes called proteases or by in...sport through a membrane Separation of viral proteins that were translated from a monocistronic mRNA Digestion of proteins from foods as a source of ...

Proteome

...stems. A cellular proteome is the collection of proteins found in a particular cell type under a particu...anism can be conceptualized as the complete set of proteins from all of the various cellular proteomes. This is very roughly the protein equivalent of the geno...

Protein

... function of all living cells and viruses .Many proteins are enzymes or subunits of enzymes. Other proteins play structural or mechanical roles, such as those that form the struts and joints of the cytoskele...

Protein biosynthesis

...osynthesis is the process in which cells build proteins . The term is sometimes used to refer only to prot...anslation, the message of mRNA is decoded to make proteins . Initiation and elongation occur when the ribosome recognizes the starting codon on the mRNA strand...

Proteasome

...aped multi- protein complex that can digest other proteins into short polypeptides and amino acids in an ATP -driven reaction. The proteasome is hollow, providing an enclosed space for protein digestion, and has openings at the two ends to allow entry of the targeted protein. 26S proteasome The 26 S...

Promoter

...er RNA creation - and, by extension, control which proteins the cell manufactures. The perfect promoter is called a canonical sequence . Contents showTocToggle("show","hide") 1 Promoter elements 2 Promoter sequences 2.1 Prokaryotic promoters 2.1.1 Probability of occurrence of each ...

Prion

...y transfers the pathological conformation to the proteins synthesized by the cell. A breakthrough occurred ... Not all prions are dangerous; in fact, prion-like proteins are found naturally in many (perhaps all) plants and animals. Because of this, scientists reasoned t...

Peptide

...It has also been documented that when certain food proteins such as gluten , casein , egg protein and spi...orphine and dermorphine . Peptides differ from proteins , which are also long chains of amino acids, by virtue of their size. Traditionally, those peptide c...

Plasmid

...de for (determine the production of) colicines , proteins that can kill other bacteria. Degrative plasmi...he gene of interest. Just as the bacteria produces proteins to confer its antibiotic resistance, it can also be induced to produce large amounts of proteins fro...

Cell membrane

...ut. Cell surface membranes often contain receptor proteins and cell adhesion proteins . There are also other proteins with a variety of functions.These membrane proteins are important fo...

Phylogenetic tree

...netic tree¹ for myosin , a superfamily of proteins . Links to other pictures are given in the Pictures on the Web subsection below. There are three main methods of constructing phylogenetic trees: Distance based methods such as Neighbour Joining , Parsimony based methods such as Maximum Parsim...

Photosystem

...otosystems use ferredoxin like iron-sulfur cluster proteins as terminal electron acceptors, while type II phot... of 660 nanometers , it associates with different proteins in each type of photosytem to slightly shift its optimal wavelength, producing two distinct photosys...

Photosystem

...otosystems use ferredoxin like iron-sulfur cluster proteins as terminal electron acceptors, while type II phot... of 660 nanometers , it associates with different proteins in each type of photosytem to slightly shift its optimal wavelength, producing two distinct photosys...

Photosynthesis

...ch is then converted into glucose and sometimes proteins ). These are called light-independent reactions , or dark reactions, since they can occur in the absence of light. However, when oxygen is abundant in the chloroplast in comparison to carbon dioxide due to some reason, such as competition in a den...

Light-dependent reaction

...an electron transport chain . This is a series of proteins embedded in a biological membrane that transfers high-energy electrons from one to another, accomplishing various activities along the way as the electron drops in energy level. The electrons originate when a photon of sunlight strikes a chlorophyl...

Phosphorylation

...ively rare. However, since tyrosine phosphorylated proteins are relatively easy to purify using antibodies , tyrosine phosphorylation sites are relatively well understood. Histidine and aspartate phosphorylation occurs in prokaryotes as part of two-component signalling. Other kinds ATP , the "hi...

Phospholipid

...ble, and has fluid properties, in which embedded proteins and phospholipid molecules are constantly moving l...s that act as a solvent for all the substances and proteins within it, so proteins and lipid molecules are basically free to diffuse laterally through the lipid...

Phage

...They do not kill the cell, but monitor ( via some proteins they code for) the status of their host. When the host cell shows signs of stress (meaning it might be about to die soon), the endogenous phages become active again and start their reproductive cycle, resulting in the lysis of the host cell. An examp...

Peroxisome

...s may be formed directly. They also have membrane proteins that are critical for various functions, such as for importing proteins into their interiors and to proliferate and segregate into daughter cells. Peroxisomes function to ...

Peripheral membrane protein

Peripheral membrane proteins are proteins that adhere only loosely to the biological membrane with which they are associated. These molecul...

Peptide

...It has also been documented that when certain food proteins such as gluten , casein , egg protein and spi...orphine and dermorphine . Peptides differ from proteins , which are also long chains of amino acids, by virtue of their size. Traditionally, those peptide c...

Peptide bond

...molecule is called an amide . Polypeptides and proteins are chains of amino acids held together by peptid...lysis (the adding of water). The peptide bonds in proteins are metastable , meaning that in the presence of water they will break spontaneously, releasing abo...

Paternity testing

...BO blood group typing , analysis of various other proteins and enzymes , or using HLA antigens . For the most part however, DNA has all but taken over all the other forms of testing. The DNA of an individual is almost exactly the same in each and every somatic cell . Sexual reproduction brings th...

Passive transport

...cules across the cell membrane via special carrier proteins that are embedded within the cellular membrane. A lot of large molecules, such as glucose, are insoluble in lipids and too large to fit through the membrane pores. Therefore, it will bind with its specific carrier proteins, and the complex will then ...

Oswald Avery

...eated with protease enzymes , which removed the proteins from the cells before the remainder was placed wit.... The R strain bacteria transformed, meaning that proteins didn't carry the genes for causing the disease. Then the remnants of the S strain bacteria were tre...

Osmosis

... 6 See also Explanation Solutes, such as proteins or simple ions , dissolve in a solvent such as water. This raises the concentration of the solute in these areas. The solvent then diffuses to these areas of higher solute concentration to equalize the concentration of the solute throughout the sol...